Monday, November 18, 2013

Glaze Problems . . . Not

Here is a picture of the speckling in our glaze, as I reported in the last post:


Snowstorm in the pines.

This is a particularly spotty example and it makes us grimace every time we see pieces like this one.

But after a lot of sweating and fretting, Ben finally came up with the idea that we might solve the problem by painting slip on the pieces we had already thrown. It was the only way we could get a good number of pots to Joyce, in Wyoming, in time for her shows this fall. The slip we’re using is a recipe we got from a demonstration we went to in Red Lodge about a year ago.

So we gave it a sample trial. It seemed to work really well, so we painted slip on a good kiln load of ware.




Then we bisque fired them again – to sinter the slip so we wouldn’t have problems with it peeling when we dipped the piece in a tub of glaze – then glazed and fired them to cone 6. While we waited for the load to fire and cool, we painted slip on another load.

When that first load came out we didn’t exactly sigh with relief, though. There was still some speckling and we had some pitting as well. I figured out, after a couple of loads, that too much slip will cause the drying glaze to pit, while not enough will still allow some speckling. It’s a fine line that we haven’t entirely figured out, but now all the ware we had on hand for white ware with the old clay is slipped and ready to fire again.

But the pieces we’re firing now are far better than the ones we fired before we painted on the slip, so we carried on and will have a pile of work to deliver to Powell, Wyoming this Wednesday, just in time for Joyce’s first holiday show this weekend.


But we’re glad we got some different clay from Helena, even though we are not especially happy with this particular clay body. We won’t have to fire the ware three times, which makes our pots that much more expensive to produce.

The texture of the clay from Helena is so fine, though, that I cannot throw platters unless I add some coarser grit material (I use what we potters call grog), since my platters out of this clay have all cracked in half, and the clay is a bit too dark for our white ware.

It is, however, the only real choice we can get without shipping it in, which can take two weeks or longer as we wait for a local truck to travel to and from the right places (otherwise shipping costs more than the clay); so we’re just going with it for now. We have enough to get us through – so long as I can get started soon – while I work through some experiments to come up with a recipe for a new clay body that we hope we’ll like a whole lot more.

Then we’ll be able to figure out which glaze recipe will be most compatible for the new clay.


Wow, impressive. How many run-on sentences did I just write?

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